Why You Get a Blue Screen After Enabling AHCI Mode in BIOS After Installing the OS

After installing Windows 7, the SATA ports work normally in IDE mode, but after switching from IDE to AHCI mode in the BIOS, the computer fails to boot and shows a blue screen.
Method 1:
First set the AHCI mode under the BIOS advanced SATA options to IDE, and set the computer to boot from a USB drive;
Restart the computer and enter the PE system, where the drive can be detected. Click “Automatically install system to drive C” to start copying files. When copying finishes and you are prompted that the computer will restart in a few seconds, press the key to enter the BIOS as the computer shuts down and restarts;
Change the original IDE mode to AHCI mode and set the drive as the first boot device. Save and restart, then proceed with the system installation; the screen will go black twice. During the earlier clean installation of Windows 7, the installation disc only copied and extracted some Windows files without registering and installing the hardware. Once AHCI mode is set and the computer boots into the installer, it registers the hardware and installs the drivers. After this is complete, the computer will run normally from the drive with AHCI mode enabled.
Method 2:
If you enable AHCI for the SATA drive in the BIOS after Windows has been installed, the system will fail to boot, and will only return to normal after switching back to IDE mode. In this case, modify the registry and then enable AHCI mode:
Click the “Start” button, type “regedit” in the search box and press Enter to open the “Registry Editor” window. Although Windows 7 does not show the “Run” command in the Start menu by default, the search box can serve the same purpose (or simply press Windows key + R and type the command).